Hand held surgical device for manipulating an internal magnet assembly within a patient

ABSTRACT

A device for manipulating a magnetic coupling force across tissue in response to a monitored coupling force is described. The device includes a magnetic field source assembly, a positioning assembly operatively connected to the magnetic field force assembly, and a magnetic coupling force monitor. The magnetic field source assembly includes magnets that provide an external magnetic field source for providing a magnetic field across tissue. The positioning assembly adjusts the position of the magnetic field source. The magnetic field creates a magnetic coupling force between the external magnetic field source and an object positioned in use in a patient during a procedure, wherein the object has or is associated with an internal magnetic field.

PRIORITY

This application claims the benefit of U.S. Provisional Application Ser.No. 61/453,824 filed Mar. 17, 2011, the contents of which areincorporated herein by reference in their entirety.

PARTIES TO A JOINT RESEARCH AGREEMENT

Ethicon Endo-Surgery, Inc., an Ohio corporation, and SouthwesternMedical Center at Dallas having a place of business at 5323 Harry HinesBlvd. Dallas, Tex. 75390, are parties to a Joint Research Agreement.

Ethicon Endo-Surgery, Inc., an Ohio corporation, and The University ofTexas at Arlington having a place of business at 710 S. Nedderman DriveArlington, Tex. 76019, are parties to a Joint Research Agreement.

BACKGROUND

i. Field of the Invention

The present application relates to methods and devices for minimallyinvasive therapeutic, diagnostic, or surgical procedures and, moreparticularly, to magnetic guidance systems for use in minimally invasiveprocedures.

ii. Description of the Related Art

In a minimally invasive therapeutic, diagnostic, and surgicalprocedures, such as laparoscopic surgery, a surgeon may place one ormore small ports into a patient's abdomen to gain access into theabdominal cavity of the patient. A surgeon may use, for example, a portfor insufflating the abdominal cavity to create space, a port forintroducing a laparoscope for viewing, and a number of other ports forintroducing surgical instruments for operating on tissue. Otherminimally invasive procedures include natural orifice transluminalendoscopic surgery (NOTES) wherein surgical instruments and viewingdevices are introduced into a patient's body through, for example, themouth, nose, or rectum. The benefits of minimally invasive procedurescompared to open surgery procedures for treating certain types of woundsand diseases are now well-known to include faster recovery time and lesspain for the patient, better outcomes, and lower overall costs.

Magnetic anchoring and guidance systems (MAGS) have been developed foruse in minimally invasive procedures. MAGS include an internal deviceattached in some manner to a surgical instrument, laparoscope or othercamera or viewing device, and an external hand held device forcontrolling the movement of the internal device. Each of the externaland internal devices has magnets which are magnetically coupled to eachother across, for example, a patient's abdominal wall. In the currentsystems, the external magnet may be adjusted by varying the height ofthe external magnet.

The foregoing discussion is intended only to illustrate various aspectsof the related art in the field of the invention at the time, and shouldnot be taken as a disavowal of claim scope.

SUMMARY

A device is described herein for manipulating a magnetic coupling forceacross tissue based on the monitored coupling force generated betweenthe external and internal magnets. In one embodiment, the deviceincludes a magnetic field source assembly that comprises a firstmagnetic field source for providing a magnetic field across tissue. Thefirst magnetic field provides a magnetic coupling force between thefirst magnetic field source and an object that provides a secondmagnetic field. The device also includes a positioning assemblyoperatively connected to the magnetic field force assembly for adjustingthe position of the first magnetic field source, and a magnetic couplingforce monitor.

The device may further include an outer housing that contains themagnetic field source assembly and preferably also contains at least aportion of the positioning assembly. In certain embodiments, thepositioning assembly includes a driver for adjusting the elevationalposition of the magnetic field force assembly within the outer housing,and an actuator for moving the driver.

In several embodiments, the magnetic field source assembly may comprisea first magnetic field source for providing, in use, a magnetic fieldacross tissue, the first magnetic field providing a magnetic couplingforce between the first magnetic field source and an object providing asecond magnetic field source; a positioning assembly operativelyconnected to the magnetic field force assembly for adjusting theposition of the first magnetic field source, the positioning assemblyhaving a driver for adjusting the elevational position of the magneticfield force assembly and an actuator for moving the driver; and amagnetic coupling force monitor.

In certain embodiments of the device, the object is structured forpositioning in use on an internal site of a patient and has associatedtherewith a second magnetic field source for forming with the firstmagnetic field source the magnetic coupling force across tissue.

The magnetic field source assembly may further include a magnet housingand a magnet support. In certain embodiments, first magnetic fieldsource may have at least one magnet and preferably two magnets, held bythe magnet support and suspended within the magnet housing. A bracketmember may be provided for connecting the magnet housing to the driverof the positioning assembly. Movement of the driver will adjust theelevational position of the magnet housing within the outer housing.

In one embodiment, the actuator of the positioning assembly may be amanually controllable actuator operatively connected to the driver. Forexample, the manually controllable actuator may be a rotatable knobmounted on a proximal end of the driver which, when turned, rotates thedriver to adjust the elevational position of the magnet housing.

Some embodiments of the device may include a spring assembly forsuspending the magnet and magnet support within the magnet housing. Thespring assembly may include a spring mounted at its distal end on themagnet support and operatively suspended at its proximal end from themagnet housing, and biased toward the proximal end thereof.

In certain embodiments, the spring assembly may also include a retainerconnected through the bracket to the magnet housing and a suspensionmember connected to the magnet support. The retainer is preferablystructured to secure thereto the proximal end of the spring and thesuspension member is preferably structured to secure thereto the distalend of the spring.

In certain embodiments, the suspension member is operatively connectedto the magnetic coupling force monitor. The magnet housing may define afirst window therethrough and the outer housing may define a secondwindow therethrough aligned with the first window. In certainembodiments, the magnetic coupling force monitor may comprise anindicator tab that extends from the suspension element through, and ismovable up and down, in a proximal or distal direction, within, each ofthe first and second windows. Indicia may be marked on an exteriorsurface of the outer housing adjacent the second window indicative ofthe coupling force experienced by the magnet.

Some embodiments of the actuator may include a gear set operativelyconnected to the driver and a motor operatively connected to the gearset for motorized control of the driver.

The device may be provided with an electromechanical automaticallyadjusting closed loop system for controlling the magnetic coupling forcebased on the sensed force between the external and internal magneticfield sources.

Certain embodiments of the magnetic coupling force monitor may include asensor positioned at a distal end of the magnet support on which themagnet support rests. The sensor is preferably calibrated to sense anychange in the force exerted on the sensor. A communication circuit ispreferably provided from the sensor to the motor to control theoperation of the motor in response to the sensed changes in force.

The magnetic coupling force monitor may further include a transducerpositioned on the floor of the magnet housing for measuring changes inthe magnetic coupling force between the magnet and the object andtransmitting signals representative of the measured change in themagnetic coupling force; a control unit for receiving the signals fromthe transducer; and, a processor in communication with the control unitfor converting the received signals to output signals for signaling themotor to adjust the elevation of the magnet housing until apredetermined magnetic coupling force is measured by the transducer.

The positioning assembly may also include a fail-safe mechanism forpreventing travel of the driver outside of predetermined limits. Thefail-safe mechanism may be an optical sensor having a channel, a lightsource for sending a beam of light across the channel, a light blockingmember structured for passage through the channel and operativelyconnected to the magnetic field source assembly, and a receiver fordetecting the presence or absence of the beam of light across thechannel and for signaling the presence or absence of the beam of lightto the motor to stop the motor when the beam of light is blocked by theblocking member.

The fail-safe mechanism may alternatively be a set of trip switches forsignaling the motor to stop when the driver travels outside of thepredetermined limit.

FIGURES

Various features of the embodiments described herein are set forth withparticularity in the appended claims. The various embodiments, however,both as to organization and methods of operation, together withadvantages thereof, may be understood in accordance with the followingdescription taken in conjunction with the accompanying drawings asfollows.

FIG. 1 is a view of the front of an embodiment of the manuallycontrollable hand held manipulation device.

FIG. 2 is a view of some internal components of the embodiment of FIG. 1through a transparent outer housing.

FIGS. 3A, B and C are perspective views of the top, bottom, and partialinterior, respectively, of an embodiment of the magnetic field sourceassembly.

FIG. 4 is a perspective view of the bottom of an embodiment of themagnets and magnet support of the assembly of FIG. 3.

FIG. 5 is a perspective view of the magnetic field source assembly witha portion of the drive assembly and the magnetic coupling force monitor.

FIG. 6 is a perspective view into the interior of the embodiment of themanually controllable hand held manipulation device of FIG. 1, with thecover removed.

FIG. 7 is a view of the spring and indicator in the manuallycontrollable hand held manipulation device.

FIGS. 8A and B are partial section views of the spring and indicatorthrough the line A-A and B-B, respectively, of FIG. 5.

FIG. 9 is a perspective view of an embodiment of an automatic hand heldmanipulation device with a transparent outer housing to show someinternal components of the automatic hand held manipulation device.

FIG. 10 is a front view of the embodiment of FIG. 9 with a transparentouter housing.

FIG. 11 is a view of an embodiment of an optical fail-safe mechanism ofthe embodiment of FIGS. 9 and 10.

FIG. 12 is a schematic view of components of an embodiment of a sensorsystem usable in the hand held manipulation device.

FIG. 13 is a section view of the device of FIG. 9.

FIG. 14 is a front view of the magnetic field source assembly of FIGS. 9and 10, with a transparent magnet housing.

FIG. 15 is a front view of an alternative embodiment of an automatichand held manipulation device with a transparent outer housing to showinternal components.

FIG. 16 is a side view of the embodiment of FIG. 15.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate various embodiments of the invention, in one form, and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DESCRIPTION

Numerous specific details are set forth to provide a thoroughunderstanding of the overall structure, function, manufacture, and useof the embodiments as described in the specification and illustrated inthe accompanying drawings. It will be understood by those skilled in theart, however, that the embodiments may be practiced without suchspecific details. In other instances, well-known operations, components,and elements have not been described in detail so as not to obscure theembodiments described in the specification. Those of ordinary skill inthe art will understand that the embodiments described and illustratedherein are non-limiting examples, and thus it can be appreciated thatthe specific structural and functional details disclosed herein may berepresentative and do not necessarily limit the scope of theembodiments, the scope of which is defined solely by the appendedclaims.

In describing and claiming the present invention, the followingterminology will be used in accordance with the definitions set outbelow.

Reference throughout the specification to “various embodiments,” “someembodiments,” “one embodiment,” or “an embodiment”, or the like, meansthat a particular feature, structure, or characteristic described inconnection with the embodiment is included in at least one embodiment.Thus, appearances of the phrases “in various embodiments,” “in someembodiments,” “in one embodiment,” or “in an embodiment”, or the like,in places throughout the specification are not necessarily all referringto the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments. Thus, the particular features, structures, orcharacteristics illustrated or described in connection with oneembodiment may be combined, in whole or in part, with the featuresstructures, or characteristics of one or more other embodiments withoutlimitation.

It will be appreciated that the terms “proximal” and “distal” may beused throughout the specification with reference to a clinicianmanipulating one end of an instrument used to treat a patient. The term“proximal” refers to the portion of the instrument closest to theclinician and the term “distal” refers to the portion located farthestfrom the clinician. It will be further appreciated that for concisenessand clarity, spatial terms such as “vertical,” “horizontal,” “up,” and“down” may be used herein with respect to the illustrated embodiments.However, surgical instruments may be used in many orientations andpositions, and these terms are not intended to be limiting and absolute.

As used herein, the term “elevational position” with respect to one ormore components means the distance of such component or components abovea floor or ground or bottom position of another component or referencepoint without regard to the spatial orientation of the respectivecomponents.

As used herein, the term “biocompatible” includes any material that iscompatible with the living tissues and system(s) of a patient by notbeing substantially toxic or injurious and not known to causeimmunological rejection. “Biocompatibility” includes the tendency of amaterial to be biocompatible.

As used herein, the term “operatively connected” with respect to two ormore components, means that operation of, movement of, or some action ofone component brings about, directly or indirectly, an operation,movement or reaction in the other component or components. Componentsthat are operatively connected may be directly connected, may beindirectly connected to each other with one or more additionalcomponents interposed between the two, or may not be connected at all,but within a position such that the operation of, movement of, or actionof one component effects an operation, movement, or reaction in theother component in a causal manner.

As used herein, the term “operatively suspended” with respect to two ormore components, means that one component may directly suspended fromanother component or may be indirectly suspended from another componentwith one or more additional components interposed between the two.

As used herein, the term “patient” refers to any human or animal onwhich a suturing procedure may be performed. As used herein, the term“internal site” of a patient means a lumen, body cavity or otherlocation in a patient's body including, without limitation, sitesaccessible through natural orifices or through incisions.

The manipulation device 10 is structured to manipulate a magneticcoupling force across living tissue 200 between objects having, orassociated with, magnetic fields. The manipulation device 10 generallyincludes a magnetic field source assembly 24, a positioning assemblyoperatively connected to the magnetic field source assembly, and amagnetic coupling force monitor.

The magnetic field source assembly 24 includes a first, or external,magnetic field source that provides a magnetic field across tissue 200.In MAGS applications, there is an object 210, as shown in FIG. 1,positioned in use on an internal site of a patient, across the tissue200 (e.g., the abdominal wall or other tissue barrier between the insideand the outside of the patient) from the manipulation device 10. Theinternal object 210 is itself or is operatively connected to anothercomponent that is a source of a second, or internal, magnetic field. Thefirst, or external, magnetic field of the magnetic field source assembly24 and the second, or internal, magnetic field source create a magneticcoupling force wherein the internal object 210 is magnetically coupledacross the tissue 200 to the magnetic field source of the manipulationdevice 10.

Lateral movement of the manipulation device 10 over the external surfaceof the tissue 200 causes a similar lateral movement of the internalobject 210 on the internal surface of the tissue. If the magneticcoupling force is too strong, however, lateral movement may be difficultdue to the resistance to movement by the strongly attracted,magnetically coupled objects, or may induce tissue trauma due to thehigh coupling force. Based on the monitored force generated between theexternal and internal magnetic field sources, the manipulation device 10described herein enables control of the magnetic coupling force tomaintain the force at a level that is strong enough to hold the internalobject 210 while allowing lateral movement of the manipulation device 10and the internal object, but without inducing excess tissue trauma.

The control that the manipulation device 10 exercises over the magneticcoupling force may be manual or automatic. In each embodiment, themanipulation device 10 may include a magnetic field source assembly 24that is suspended within an outer container 12 that provides an outerhousing for the device 10. The magnetic assembly 24 is raised andlowered, either automatically in response to a sensor, or manually inresponse to a clinician's control, to adjust the power that the externalmagnetic field source exerts over the internal object and its associatedinternal magnetic field source. Adjusting the power of the externalmagnetic field adjusts the magnetic coupling force between the externalmagnetic assembly and the internal object.

Referring to FIGS. 3A-C, the magnetic field source assembly 24 includesgenerally a magnet housing 26 having side walls 26 a and a bottom crossbar 26 b, at least one or more, and preferably two magnets 28, and amagnet support 36. The magnet support 36 includes front and rear panels48 and a midsection 50 that separates the magnets 28. The support 36 isfixed to each magnet 28 by any suitable engagement members. For example,referring to the embodiment of FIG. 4, raised rails 58 are positioned incomplementary engagement with recessed tracks 60 formed on at least aportion of facing surfaces of the front and rear panels 48 and magnets28, respectively. Those skilled in the art will appreciate that themagnets 28 may have raised surfaces and the support 36 may havecomplementary recessed surfaces to secure the magnets 28 within support36. Other suitable complementary engagement surfaces or other suitablefixation devices to secure the magnets 28 to the support 36 willsuffice.

Spacers 66 extend from the support panels 48 to maintain alignment ofthe magnets 28 within support 36.

The midsection 50 of support 36 is structured in certain embodiments todefine a lower channel 52 between the lower ends of magnets 28 formingan open space between the cross-bar 26 b, midsection 50, and theinterior facing sides 62 of magnets 28. The midsection 50 also definesan upper channel 54 between the top ends of magnets 28 forming an openspace between the top of midsection 50 and the interior facing sides 62of magnets 28. As shown in FIG. 3, a well 64 may be formed in the top ofmidsection 50.

FIGS. 5-8 illustrate an embodiment of the magnetic assembly 24 having abracket 40 connected to magnet housing 26. The bracket 40 shown in thefigures includes a top section 80 and a central post 78 that extendspartially into the channel 54 between magnets 28. Extending downwardlyfrom post 78 on opposing sides of post 78 are bracket legs 82. A flange68 extends from each side of the top section 80 of bracket 40 to seat ina chamfer on the upper edge of magnet housing 26 to hold bracket 40 inposition relative to magnet housing 26. Pins 86 protrude laterally fromeach side of central leg 82 through pin holes 90 in magnet housing sidewalls 26 a to further fix bracket 40 to magnet housing 26.

The positioning assembly may include a drive shaft 88 which extendsthrough a bore 84 in top 80 of bracket 40. In this embodiment, bore 84and drive shaft 88 are preferably threaded so that actuation of thedrive shaft 88 carries bracket 40, and with it, magnet housing 26 up anddown within the open gap 46 in outer housing 12 between the top of themagnet assembly 24 and the bottom of shaft head 74.

In certain embodiments, the position of the magnet housing 26 may beadjusted manually by the surgeon or clinician. A spring loaded scale maybe used to float the magnets 28 within the housing 26 and to monitor themagnetic coupling force. Referring to FIGS. 7 and 8A, B, a retainer 94sits in and is fixedly attached to well 64 of magnet support 36. Aspring 92 is positioned on the boss of retainer 94 that extends upwardlyinto channel 54 between magnets 28. The top of spring 92 is press fitonto a retainer 96 that is suspended from pins 98. Pins 98 protrudelaterally from each side of retainer 96 and extend into and through pinholes 76 in bracket legs 82 of bracket 40 and magnet housing 26 to fixretainer 96 to bracket 40 and magnet housing 26. The magnets 28 andmagnet support 36 are thus suspended by spring 92 within magnet housing26, allowing the magnets 28 to float above the floor of outer housing12. The magnet support 36 and magnets 28 are not fixedly attached tomagnet housing 26 or to bracket 40, but move up and down within magnethousing 26. Support 36 and magnets 28 are dimensioned to be smaller thanmagnetic housing 26 to fit within magnet housing 26 such that a gap 44is created between the floor of outer housing 12 and the bottom surfaceof magnets 28 and the magnets 28 move freely without resistance from theinterior walls of magnet housing 26.

Referring to FIG. 1, the manipulation device 10 includes outer housing12 having a top cover 14. The sides of cover 14 include openings 20 toexpose a knob 16. The cover 14 may be connected to outer housing 12 inany suitable manner, such as with pins or screws 38 or a similarfastener, through pin holes or threaded bores 70, shown in FIG. 6. Asshown in FIG. 6, outer housing 12 includes cut-out sections 72 on thetop edge to accommodate portions of knob 16. The knob 16 may be turnedin a clockwise or a counter clockwise direction by placing a hand on thetop of cover 14 and turning knob 16 with the thumb of the hand throughopenings 20. Knob 16 may include ridges 18 or any suitable texturedsurface along its circumference to facilitate tactile control over themovement of knob 16. Knob 16 is operatively connected to drive shaft 88by a shaft head 74 that is sized to engage a complementary matingsurface on knob 16.

A magnetic coupling force monitor is provided in one embodiment of themanipulation device 10 by means of an indicator bar 32 that extendslaterally from retainer 94 through windows 100 and 30 in magnet housing26 and outer housing 12, respectively. Indicia 34 in the form ofmarkings may be positioned on the outer surface of outer housing 12adjacent window 30 to represent the position of magnets 28 within magnethousing 26 and outer housing 12. The indicia are calibrated to representpredetermined loads on the magnets 28, representative of the magneticcoupling force across a patient's tissue between the external magnets 28and one or more internal magnets associated with an internal object. Forexample, the force of gravity on the external magnets pulling themagnets 28 toward the floor of magnet housing 26 is zeroed out so thatthe force reflected by the indicia 34 represent only the magneticcoupling force. A force that could cause trauma to the tissue might beindicated by one of the lower markings or the lowest marking whereas aforce that would be insufficient to hold the internal object in placemight be indicated by one of the higher markings or the highest marking.

The clinician may observe the level of the magnetic coupling force bythe position of the indicator bar 32 with respect to the markings 34. Ifthe level of the coupling force is too high or too low, the clinicianwill adjust the knob 16 in a clockwise or counter clockwise direction toraise or lower the magnet housing 26 within the outer housing 12. As theelevational position of magnet housing 26 within outer housing 12 ischanged up or down, the elevational position of magnets 28 changes up ordown as well, subject to deviations within magnet housing 26 due to themagnetic coupling force exerted on magnets 28. Because of the suspensionof the magnet support 36 and magnets 28 within magnet housing 26 and theclearance or gap 44 between the bottom of the magnets and the floor ofthe outer housing 12, the magnet support 36 and magnets 28 float withinhousing 26, so the only force measured is the magnetic coupling force ofthe magnets 28. The gap 44 may be relatively small, for example, about 5mm, but must allow enough space so that the magnets 28 are free to movein response to the magnetic attraction from the second magnetic fieldsource associated with the internal object in the patient. The spring 92is biased toward the retainer 96, so, after accounting for gravity, themagnetic coupling force is the force pulling the magnets 28 downwardly,in the distal direction.

In certain embodiments, the positioning assembly may be automatic. Incertain automated embodiments, as shown for example in FIGS. 9 through11 and 13, the positioning assembly includes a shaft 88, preferably ascrew drive, a drive gear 102, and a pinion gear 104. The pinion gear104 is attached to the drive gear 102. A motor 106 drives the piniongear 104 which drives the drive gear 102, which turns the shaft 88 toraise and lower the magnetic field source assembly 24. The drive gear102 is attached to shaft 88 and is supported on thrust bearings 142. Theshaft 88 is attached to bracket 40, as described above. In the automatedembodiment, the bracket 40 is attached to the magnet housing 26 asdescribed above, so turning shaft 88 raises and lowers the magnethousing 26 within outer housing 12. Whether the magnet housing 26 israised or lowered, the magnet set still floats within the magnet housing26 so the magnet 28 can respond to any magnetic pull exerted by theinternal magnetic field source within the patient.

In the automated embodiments, as shown for example, in FIGS. 10, 13 and14, a sensor 116 is positioned within the magnet housing 26, fixed tocross-bar 26 b of the housing 26 in channel 54. The sensor 116 may be,for example, a transducer, a piezoelectric film sensor, or a load cell.The bottom surface of mid section 50 of magnet support 36 rests on thesensor 116. In use, the magnetic force of the internal magnetic fieldsource attracts the magnets 28 in the external manipulation device 10.The magnetic coupling force pulls the magnets 28 against the sensor 116.The sensor 116 senses the force and communicates the sensed force to acontrol unit 120. Magnetic field lines are established by the magneticfield between the external and internal magnets, pulling the magnets inthe magnet housing 26 down, toward the internal magnets on the objectwithin the patient. As the downward pull increases, it pulls themagnetic support 36 harder against the sensor 116, causing the sensor116 to measure and register a greater force against it. The sensor 116signals the calculated force back to the control unit 120 wirelessly orvia circuitry, such as wire 154 or 114. The sensor 116 is adjusted tohave a zero point accounting for gravity plus the weight of the magnethousing 26, magnets 28, and magnet support 36.

Those skilled in the art will appreciate that other types of sensors maybe used. A LCD screen may be provided to show the force generationbetween the internal and external magnets.

If sensor 116 is a load cell type of sensor, for example, it feeds theload signal to a signal conditioner. The load cell 116 is acted upon bythe attractive forces between the internal and the external magnets. Theload cell 116 strains internally and the resulting strain is measured interms of electrical resistance, using current provided by any suitablepower supply. The signal conditioner, which may be contained within thecontrol unit 120, amplifies the signal from the load cell and then asuitable algorithm may be used to calculate the actual force which isthen used to drive the motor 106 at a calculated speed and duration toadjust the force.

The signal is sent by the sensor 116 to the control unit 120 which isequipped with a receiver to receive the signals and where softwareanalyzes the received signals, and sends output signals to instruct themotor 106, such as a stepper type motor, to drive the drive shaft 88,which moves the magnet housing 26 up or down sufficiently to match apredetermined force. When the predetermined force is sensed by sensor116, the sensed signals are communicated to the control unit 120 which,as before, instructs the motor 106 to stop. The continuous monitoring inuse of the magnetic coupling force provides an automatic closed loopfeedback system to control the magnetic coupling force. The power supplyand control unit 120 may be on any suitable printed circuit board andpackaged within the outer housing 12 of the manipulation device 10. FIG.12 shows a schematic of the power supply 118 to a transducer 116 and thesignals to and from the control unit 120.

The predetermined force will be the minimum force that necessary toattract and accurately control the internal object carried by theinternal magnet. The internal magnet must be held with enough magneticforce to prevent it from falling away from the internal body wall. Themaximum amount of force would be less than a force that compresses orsqueezes the tissue enough to cause tissue trauma. The surgeon has to beable to move the external magnet relatively easily across the patient'sbody to control the internal magnet without so much drag that movementis difficult or would cause tissue trauma.

The device 10 preferably includes a fail safe mechanism to prevent themotor 106 from moving the magnet housing 26 up or down too far. Thedevice 10 may, for example, include an optical sensor 108, shown inFIGS. 9-11. The optical sensor 108 has a slot 132 through at least aportion thereof dividing the sensor into two parts, a light sourceportion 136 and a receiver portion 134. A light emitting diode (LED)resides in light source portion 136 of the optical sensor 108 and areceiver resides in the receiver portion 134. Light is generated insidethe optical sensor 108 by the LED and beamed across the slot 132 througha light path 138 to the receiver portion 134. Pin connectors 112 fromthe optical sensor 108 plug into the circuit board 150, or wires may goto a printed circuit board which contains the hardware for running thesensor 116 and power sensors. A flag 110 has one end attached to thebracket 40 so that it moves up and down with the magnet housing 26 andhas a second end having a top cross bar 130 that passes through the slot132 of the optical sensor 108 as the flag moves up and down. A post 140joining the first end to second end defines an open section between thetwo ends. When the flag 110 is positioned such that the top cross bar130 of the second end blocks the path 138 for the beam of light from theLED to the receiver, the signals to the software on the circuit board150 through connectors 112 or wires are interrupted causing the motor106 to stop, thereby stopping the downward movement of the drive shaft88 and the magnet housing 26. The magnet housing 26 is prevented frompressing against the bottom of the outer housing 12. When the flag 110is positioned such that the top cross bar 130 of the second end is abovethe path 138 of the beam of light, the beam of light passes through theopening in the flag to the receiver in the receiver portion 134 of theoptical sensor 108, which in turn signals the motor 106 through thecircuit board 150 to drive the magnet housing 26 up or down.

After the motor 106 stops because the beam of light is blocked, themotor 106 will start again only when the sensor 116 signals that theforce against the sensor 116 has been reduced. If the magnetic pull onthe magnets 28 is reduced, the sensor 116 will sense the change andsignal the control unit 120. The software logic will restart the motor106 to allow the drive shaft 88 to move the magnet housing 26 up. Themovement of the magnet housing 26 brings the flag 110 up with it, movingthe top cross bar 130 of the second end above the light path and openingin the light path. If the magnet housing 26 rises too far, the first endof the flag will block the light path and in turn cause the motor 106 tostop. The magnet housing 26 is prevented from going up too far againstthe top of the outer housing 12.

The optical sensor 108 is fixed to a spacer piece and sits in a fixedposition within a pocket in the outer housing 12 above the magnethousing 26. Those skilled in the art will recognize that other types ofoptical sensors and other types of fail safe mechanisms, including butnot limited to trip switches, may be used.

Another embodiment of the automated manipulation device is shown inFIGS. 15 and 16. The motor 106′ of the positioning assembly in thisembodiment is positioned beside the magnet housing 26 rather than aboveit, as shown in FIGS. 9-11. The motor 106′ is connected by a shaft 104′to a pinion gear 102′ which turns a ring gear 152. A screw drive 88′ isoperatively connected to the ring gear 152.

A sensor 116′, such as a piezo electric pressure sensitive film, ispositioned on the floor of the outer housing 12′ beneath the magnethousing 26′. The sensor 116′ is electrically connected to a printedcircuit board 120′ by wire 154. The circuit board 120′ may utilize aprogrammable controller (e.g., EPROM) to analyze signals from the sensor116′, in the manner generally described above. The circuit board 120′ isalso electrically connected to a pressure transducer 160 positionedbeneath the cover 14′ of the outer housing 12′. In order to isolate theforce applied by the clinician on the cover 14′ of outer housing 12′from that of the magnetic coupling force between the external magnet 28on the bottom of the outer housing 12′ and the internal magnet, thecover 14′ is supported by suspension springs 162. Changes in the forceexerted on suspension springs 162 are read by a pressure transducer 160.As shown in FIG. 16, the cover 14′ fits in a cut-out portion on the topedge of outer housing 12′ and rests on suspension springs 162. The cover14′ compresses springs 162 which are electrically connected to thepressure transducer 160. The load signal from the suspension springs 162is analyzed so that the amount of load induced by the clinician issubtracted out from the load induced by the magnetic coupling force.

The embodiments of the devices described herein may be introduced insidea patient using minimally invasive or open surgical techniques. In someinstances it may be advantageous to introduce the devices inside thepatient using a combination of minimally invasive and open surgicaltechniques. Minimally invasive techniques may provide more accurate andeffective access to the treatment region for diagnostic and treatmentprocedures. To reach internal treatment regions within the patient, thedevices described herein may be inserted through natural openings of thebody such as the mouth, nose, anus, and/or vagina, for example.Minimally invasive procedures performed by the introduction of variousmedical devices into the patient through a natural opening of thepatient are known in the art as NOTES™ procedures. Some portions of thedevices may be introduced to the tissue treatment region percutaneouslyor through small-keyhole-incisions.

Endoscopic minimally invasive surgical and diagnostic medical proceduresare used to evaluate and treat internal organs by inserting a small tubeinto the body. The endoscope may have a rigid or a flexible tube. Aflexible endoscope may be introduced either through a natural bodyopening (e.g., mouth, nose, anus, and/or vagina) or via a trocar througha relatively small-keyhole-incision incisions (usually 0.5-2.5 cm). Theendoscope can be used to observe surface conditions of internal organs,including abnormal or diseased tissue such as lesions and other surfaceconditions and capture images for visual inspection and photography. Theendoscope may be adapted and configured with working channels forintroducing medical instruments to the treatment region for takingbiopsies, retrieving foreign objects, and/or performing surgicalprocedures.

All materials used that are in contact with a patient are preferablymade of biocompatible materials.

Preferably, the various embodiments of the devices described herein willbe processed before surgery. First, a new or used instrument is obtainedand if necessary cleaned. The instrument can then be sterilized. In onesterilization technique, the instrument is placed in a closed and sealedcontainer, such as a plastic or TYVEK®bag. The container and instrumentare then placed in a field of radiation that can penetrate thecontainer, such as gamma radiation, x-rays, or high-energy electrons.The radiation kills bacteria on the instrument and in the container. Thesterilized instrument can then be stored in the sterile container. Thesealed container keeps the instrument sterile until it is opened in themedical facility. Other sterilization techniques can be done by anynumber of ways known to those skilled in the art including beta or gammaradiation, ethylene oxide, and/or steam.

Although the various embodiments of the devices have been describedherein in connection with certain disclosed embodiments, manymodifications and variations to those embodiments may be implemented.For example, different types of end effectors may be employed. Also,where materials are disclosed for certain components, other materialsmay be used. The foregoing description and following claims are intendedto cover all such modification and variations.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

What is claimed is:
 1. A device for manipulating a magnetic couplingforce across tissue comprising: a magnetic field source assemblycomprising a first magnetic field source for providing, in use, amagnetic field across tissue, the first magnetic field source providinga magnetic coupling force between the first magnetic field source and anobject providing a second magnetic field source; a positioning assemblyoperatively connected to the magnetic field source assembly foradjusting an elevational position of the first magnetic field source,the positioning assembly having a driver for adjusting the elevationalposition of the magnetic field source assembly and an actuator formoving the driver; a magnetic coupling force monitor; and an outerhousing containing at least the magnetic field source assembly, theouter housing configured to allow elevational adjustment of the magneticfield source assembly within the housing; wherein the magnetic fieldsource assembly further comprises: a magnet housing, a magnet support,and the first magnetic field source comprises at least one magnet, theat least one magnet being held by the magnet support and suspendedwithin the magnet housing.
 2. The device of claim 1 further comprising abracket member for connecting the magnet housing to the driver.
 3. Thedevice of claim 2 further comprising a spring assembly for suspendingthe at least one magnet and magnet support within the magnet housing. 4.The device of claim 3 wherein the spring assembly comprises a springhaving a proximal end and a distal end, the spring being mounted at thedistal end on the magnet support and operatively suspended at theproximal end from the magnet housing, the spring being biased toward theproximal end thereof.
 5. The device of claim 4 wherein the springassembly further comprises: a retainer operatively connected through thebracket member to the magnet housing, the retainer being structured tosecure thereto the proximal end of the spring; and, a suspension memberconnected to the magnet support and being structured to secure theretothe distal end of the spring.
 6. The device of claim 5 wherein thesuspension member is operatively connected to the magnetic couplingforce monitor.
 7. The device of claim 6 wherein the magnet housingdefines a first window therethrough and the outer housing defines asecond window therethrough aligned with the first window; and, themagnetic coupling force monitor comprises an indicator tab that extendsfrom the suspension member through each of the first and second windows,the indicator tab movable proximally and distally within the first andsecond windows, and indicia marked on an exterior surface of the outerhousing adjacent the second window indicative of a magnetic couplingforce experienced by the at least one magnet.
 8. The device of claim 7wherein the actuator is a manually controllable actuator having arotatable knob mounted on a proximal end of the driver which whenturned, rotates the driver to adjust an elevational position of themagnet housing to adjust the magnetic coupling force in response to theindicated magnetic coupling force.
 9. The device of claim 2 wherein theactuator is a manually controllable actuator operatively connected tothe driver.
 10. The device of claim 9 wherein the manually controllableactuator is a rotatable knob mounted on a proximal end of the driverwhich, when turned, rotates the driver to adjust an elevational positionof the magnet housing within the outer housing.
 11. The device of claim10 wherein the actuator further comprises a gear set operativelyconnected to the driver and a motor operatively connected to the gearset for motorized control of the driver.
 12. The device of claim 11wherein the positioning assembly further comprises a fail-safe mechanismfor preventing travel of the driver outside of predetermined limits. 13.The device of claim 12 wherein the fail-safe mechanism is an opticalsensor having a channel, a light source for sending a beam of lightacross the channel, a light blocking member structured for passagethrough the channel and operatively connected to the magnetic fieldsource assembly, and a receiver for detecting the presence or absence ofthe beam of light across the channel and for signaling the presence orabsence of the beam of light to the motor to stop the motor when thebeam of light is blocked by the light blocking member.
 14. The device ofclaim 12 wherein the fail-safe mechanism is a set of trip switches forsignaling the motor to stop when the driver travels outside of thepredetermined limits.
 15. The device of claim 11 wherein the magneticcoupling force monitor comprises a sensor positioned at a distal end ofthe magnet support on which the magnet support rests, the sensor beingcalibrated to sense any change in a force exerted on the sensor, and acommunication circuit from the sensor to the motor to control anoperation of the motor in response to the monitored changes in the forceexerted on the sensor.
 16. The device of claim 11 wherein the magneticcoupling force monitor comprises: a transducer positioned adjacent afloor of the magnet housing for measuring changes in a magnetic couplingforce between the at least one magnet and the object and fortransmitting signals representative of a measured change in the magneticcoupling force; a control unit for receiving the signals from thetransducer; and, a processor in communication with the control unit forconverting the received signals to output signals for signaling themotor to adjust an elevation of the magnet housing until a predeterminedmagnetic coupling force is measured by the transducer.